Grant-free downlink transmission

ABSTRACT

Methods, systems, and devices for wireless communications are described. The described techniques generally support downlink transmissions. For example, a user equipment (UE) may receive a resource configuration for reception of a downlink transmission within a repetition window, the resource configuration including an indicator of a repetition window size for the downlink transmission. The UE may monitor, according to the resource configuration, one or more transmission time intervals (TTIs) of the repetition window for reception of the downlink transmission. In some cases, the downlink transmission may be a grant-free downlink transmission. Here, the UE may attempt to decode the grant-free downlink transmission during the one or more TTIs based at least in part on the repetition window size. Using the described techniques, the UE may efficiently determine one or more decoding parameters for the grant-free downlink transmission, thereby providing benefits in terms of latency reduction, power consumption, etc.

CROSS REFERENCES

The present Application for Patent claims the benefit of U.S.Provisional Patent Application No. 62/609,266 by HOSSEINI et al.,entitled “GRANT-FREE DOWNLINK TRANSMISSION,” filed Dec. 21, 2017,assigned to the assignee hereof, and expressly incorporated by referenceherein.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to grant-free downlink transmission.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform-spread-OFDM (DFT-s-OFDM). A wireless multiple-accesscommunications system may include a number of base stations or networkaccess nodes, each simultaneously supporting communication for multiplecommunication devices, which may be otherwise known as user equipment(UE).

Some wireless communications may require or benefit from low latencyaccess. For example, ultra-reliable low latency communications (URLLC)may achieve such low latency through the use of small packet sizes,short transmission intervals, or the like. In some wireless systems,downlink transmissions (from a base station to a UE) may be scheduled,which scheduling may consume wireless resources and introduce overheadfor the system. This overhead may, in turn, increase latency and maytherefore be undesirable in some cases (e.g., for URLLC). Improvedtechniques for downlink transmissions that support low latencycommunications may thus be desired.

SUMMARY

The described techniques relate to improved methods, systems, devices,or apparatuses that support grant-free downlink transmission. Generally,the described techniques provide for one or more frameworks forgrant-free downlink transmissions, which frameworks may be leveraged bya user equipment (UE) to decode the grant-free downlink transmissions.Specifically, the UE may be configured (e.g., via radio resource control(RRC) signaling) with parameters (e.g., time/frequency resources, atransport block size (TBS), a redundancy version (RV) sequence, arepetition window size, etc.) for the grant-free downlink transmission.Based on applying the configured parameters within the one or moreframeworks discussed below, the UE may efficiently decode a grant-freedownlink transmission. For example, the reduced number of blind decodingattempts supported by aspects of the following (e.g., as compared to anunconstrained search across candidate RV indices and/or hybrid automaticrepeat request (HARQ) process identifications (IDs)) may provide for lowlatency communications (e.g., by allowing a downlink transmission to bedecoded within a threshold amount of time corresponding to the lowlatency process).

A method of wireless communication at a UE is described. The method mayinclude receiving a resource configuration for reception of a downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the downlinktransmission, monitoring, in accordance with the resource configuration,one or more transmission time intervals (TTIs) of the repetition windowfor reception of the downlink transmission, and attempting to decode thedownlink transmission during the one or more TTIs of the repetitionwindow based on the repetition window size.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the processor to cause the apparatusto receive a resource configuration for reception of a downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the downlinktransmission, monitor, in accordance with the resource configuration,one or more transmission time intervals (TTIs) of the repetition windowfor reception of the downlink transmission, and attempt to decode thedownlink transmission during the one or more TTIs of the repetitionwindow based on the repetition window size.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for receiving a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission, monitoring, in accordance with theresource configuration, one or more transmission time intervals (TTIs)of the repetition window for reception of the downlink transmission, andattempting to decode the downlink transmission during the one or moreTTIs of the repetition window based on the repetition window size.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to receive a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission, monitor, in accordance with theresource configuration, one or more transmission time intervals (TTIs)of the repetition window for reception of the downlink transmission, andattempt to decode the downlink transmission during the one or more TTIsof the repetition window based on the repetition window size.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, monitoring the one or moreTTIs of the repetition window for reception of the downlink transmissionmay include operations, features, means, or instructions for monitoringfor a first repetition of the downlink transmission in an initial TTI ofthe repetition window, where the repetition window size may be greaterthan one TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thedownlink transmission may include operations, features, means, orinstructions for identifying a series of redundancy version (RV) indicesfor the repetition window based on the resource configuration, each RVindex of the series of RV indices associated with a respective TTI ofthe repetition window, and attempting to decode the downlinktransmission during a given TTI of the repetition window based on the RVindex associated with the given TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the resource configurationmay be received via RRC signaling, the resource configuration furtherincluding a series of redundancy version (RV) indices for repeatedtransmissions of the downlink transmission within the repetition window.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thedownlink transmission may include operations, features, means, orinstructions for transmitting an indication that the downlinktransmission was successfully decoded.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the downlink transmission maybe a grant-free downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thegrant-free downlink transmission may include operations, features,means, or instructions for identifying a potential redundancy version(RV) index and a corresponding HARQ process identification (ID) for thegrant-free downlink transmission, where each decoding attempt may bebased on a unique pair of potential RV index and corresponding HARQprocess ID.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, identifying the potential RVindex and the corresponding HARQ process ID for the grant-free downlinktransmission may include operations, features, means, or instructionsfor determining a TTI index for each of the one or more TTIs of therepetition window, where the corresponding HARQ process ID for a givenTTI may be based on the TTI index for the given TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, monitoring the one or moreTTIs of the repetition window for reception of the grant-free downlinktransmission may include operations, features, means, or instructionsfor identifying, based on the resource configuration, a subset of TTIswithin the repetition window during which a first repetition of thegrant-free downlink transmission may be allowed to be transmitted, wherethe repetition window includes the subset of TTIs and at least one otherill, and monitoring for a first repetition of the grant-free downlinktransmission during at least one TTI of the subset of TTIs.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a redundancy version (RV)index of the first repetition of the grant-free downlink transmissionmay be zero (0).

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thegrant-free downlink transmission may include operations, features,means, or instructions for identifying a series of redundancy version(RV) indices for the repetition window based on the resourceconfiguration, determining one or more potential RV indices for each TTIof the repetition window, where each potential RV index for each TTI maybe based on the series of RV indices beginning at a respective TTI ofthe subset of TTIs, and attempting to decode the grant-free downlinktransmission during a given TTI of the repetition window based on theone or more potential RV indices for the given TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thegrant-free downlink transmission may include operations, features,means, or instructions for identifying a series of redundancy version(RV) indices for the repetition window based on the resourceconfiguration, identifying a HARQ process identification (ID) for eachTTI of the repetition window, where the HARQ process ID for each TTI maybe based on the series of RV indices beginning at a respective TTI ofthe subset of TTIs, and combining logarithmic likelihood ratios (LLRs)of the grant-free downlink transmission for a given TTI with apreviously received signal based on the HARQ process ID.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to decode thefirst repetition of the grant-free downlink transmission during aninitial TTI of the subset of TTIs, and attempting to decode the firstrepetition of the grant-free downlink transmission during an immediatelysubsequent TTI of the subset of TTIs based on failing to decode thefirst repetition during the initial TTI of the subset of TTIs.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, monitoring the one or moreTTIs of the repetition window for reception of the grant-free downlinktransmission may include operations, features, means, or instructionsfor monitoring for a first repetition of the grant-free downlinktransmission during any TTI of the repetition window, where therepetition window includes a set of TTIs.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thegrant-free downlink transmission may include operations, features,means, or instructions for identifying a series of redundancy version(RV) indices for the repetition window based on the resourceconfiguration, determining one or more potential RV indices for each TTIof the repetition window, where each potential RV index for each TTI maybe based on the series of RV indices beginning at any TTI of therepetition window, and attempting to decode the grant-free downlinktransmission during a given TTI of the repetition window based on theone or more potential RV indices for the given TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, attempting to decode thegrant-free downlink transmission may include operations, features,means, or instructions for identifying a series of redundancy version(RV) indices for the repetition window based on the resourceconfiguration, identifying a HARQ process identification (ID) for eachTTI of the repetition window, where the HARQ process ID for each TTI maybe based on the series of RV indices beginning at any TTI of therepetition window, and combining logarithmic likelihood ratios (LLRs) ofthe grant-free downlink transmission for a given TTI with a previouslyreceived signal based on the HARQ process ID.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining that afirst decoding hypothesis corresponding to decoding the first repetitionof the grant-free downlink transmission during a given TTI of therepetition window may have failed, and attempting to decode a secondrepetition of the grant-free downlink transmission using a seconddecoding hypothesis during the given TTI of the repetition window basedon the determination that the first decoding hypothesis may have failed.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for attempting to decodethe first repetition of the grant-free downlink transmission using anadditional decoding hypothesis during a subsequent TTI of the repetitionwindow based on the determination that the first decoding hypothesis mayhave failed.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting anindication of a capability of the UE, the capability indicating amaximum repetition window size supported by the UE, a timing within therepetition window for which the UE supports transmission of a firstrepetition of the grant-free downlink transmission, or combinations ofthe same.

A method of wireless communication at a base station is described. Themethod may include transmitting, to a UE, a resource configuration fortransmission of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission and transmitting the downlinktransmission to the UE in accordance with the resource configuration.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory.The instructions may be executable by the processor to cause theapparatus to transmit, to a UE, a resource configuration fortransmission of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission and transmit the downlinktransmission to the UE in accordance with the resource configuration.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for transmitting, to a UE, aresource configuration for transmission of a downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the downlink transmission andtransmitting the downlink transmission to the UE in accordance with theresource configuration.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission and transmit thedownlink transmission to the UE in accordance with the resourceconfiguration.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the downlinktransmission to the UE may include operations, features, means, orinstructions for transmitting a first repetition of the downlinktransmission during an initial TTI of the repetition window, the firstrepetition being associated with a first redundancy version (RV) index,and transmitting one or more additional repetitions of the downlinktransmission during one or more corresponding subsequent TTIs of therepetition window, each of the one or more additional repetitions beingassociated with a respective RV index.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the resource configurationmay be transmitted via RRC signaling, the resource configuration furtherincluding a series of redundancy version (RV) indices for the repetitionwindow.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from the UE,an indication of a successful decoding of the downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the downlink transmission maybe a grant-free downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the grant-freedownlink transmission to the UE may include operations, features, means,or instructions for identifying a subset of transmission time intervals(TTIs) within the repetition window during which a first repetition ofthe grant-free downlink transmission may be allowed to be transmitted,where the repetition window includes the subset of TTIs and at least oneother TTI, transmitting the first repetition of the grant-free downlinktransmission during a TTI of the subset of TTIs, the first repetitionbeing associated with a first redundancy version (RV) index, andtransmitting one or more additional repetitions of the grant-freedownlink transmission during one or more corresponding subsequent TTIsof the at least one other TTI, each of the one or more additionalrepetitions being associated with a respective RV index.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the grant-freedownlink transmission to the UE may include operations, features, means,or instructions for transmitting a first repetition of the grant-freedownlink transmission during any TTI of the repetition window, the firstrepetition being associated with a first redundancy version (RV) index,and transmitting one or more additional repetitions of the grant-freedownlink transmission during one or more corresponding subsequent TTIsof the repetition window, each of the one or more additional repetitionsbeing associated with a respective RV index.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from the UE,an indication of a capability of the UE, where the capability indicatesa maximum repetition window size supported by the UE, a timing withinthe repetition window for which the UE supports transmission of a firstrepetition of the grant-free downlink transmission, or combinations ofthe same.

A method of wireless communication at a UE is described. The method mayinclude a processor, memorying in electronic communication with theprocessor, instructions stored in the memory and executable by theprocessor to cause the apparatus to, monitoring, in accordance with theresource configuration, one or more transmission time intervals (TTIs)of the repetition window for reception of the downlink transmission, andattempting to decode the downlink transmission during the one or moreTTIs of the repetition window based on the repetition window size.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the process or to cause the apparatusto a process or, memory in electronic communication with the processor,instructions stored in the memory and executable by the processor tocause the apparatus to monitor, in accordance with the resourceconfiguration, one or more transmission time intervals (TTIs) of therepetition window for reception of the downlink transmission, andattempt to decode the downlink transmission during the one or more TTIsof the repetition window based on the repetition window size.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for a processor, memorying in electroniccommunication with the processor, instructionsing stored in the memoryand executable by the processor to cause the apparatus to, monitoring,in accordance with the resource configuration, one or more transmissiontime intervals (TTIs) of the repetition window for reception of thedownlink transmission, and attempting to decode the downlinktransmission during the one or more TTIs of the repetition window basedon the repetition window size.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to to a processor, memory in electroniccommunication with the processor, instructions stored in the memory andexecutable by the processor to cause the apparatus to, monitor, inaccordance with the resource configuration, one or more transmissiontime intervals (TTIs) of the repetition window for reception of thedownlink transmission, and attempt to decode the downlink transmissionduring the one or more TTIs of the repetition window based on therepetition window size.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for monitoring for a firstrepetition of the downlink transmission in an initial TTI of therepetition window, where the repetition window size may be greater thanone TTI.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a series ofredundancy version (RV) indices for the repetition window based on theresource configuration, each RV index of the series of RV indicesassociated with a respective TTI of the repetition window, and attemptto decode the downlink transmission during a given TTI of the repetitionwindow based on the RV index associated with the given TTI.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the downlink transmission maybe a grant-free downlink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a potentialredundancy version (RV) index and a corresponding HARQ processidentification (ID) for the grant-free downlink transmission, where eachdecoding attempt may be based on a unique pair of potential RV index andcorresponding HARQ process ID.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining a TTI indexfor each of the one or more TTIs of the repetition window, where thecorresponding HARQ process ID for a given TTI may be based on the TTIindex for the given TTI.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying, based onthe resource configuration, a subset of TTIs within the repetitionwindow during which a first repetition of the grant-free downlinktransmission may be allowed to be transmitted, where the repetitionwindow includes the subset of TTIs and at least one other TTI, andmonitor for a first repetition of the grant-free downlink transmissionduring at least one TTI of the subset of TTIs.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a redundancy version (RV)index of the first repetition of the grant-free downlink transmissionmay be zero (0).

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a series ofredundancy version (RV) indices for the repetition window based on theresource configuration, determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI may be based on the series of RV indices beginning at arespective TTI of the subset of TTIs, and attempt to decode thegrant-free downlink transmission during a given TTI of the repetitionwindow based on the one or more potential RV indices for the given TTI.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a series ofredundancy version (RV) indices for the repetition window based on theresource configuration, identify a HARQ process identification (ID) foreach TTI of the repetition window, where the HARQ process ID for eachTTI may be based on the series of RV indices beginning at a respectiveTTI of the subset of TTIs, and combine logarithmic likelihood ratios(LLRs) of the grant-free downlink transmission for a given TTI with apreviously received signal based on the HARQ process ID.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to decode thefirst repetition of the grant-free downlink transmission during aninitial TTI of the subset of TTIs, and attempt to decode the firstrepetition of the grant-free downlink transmission during an immediatelysubsequent TTI of the subset of TTIs based on failing to decode thefirst repetition during the initial TTI of the subset of TTIs.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for monitoring for a firstrepetition of the grant-free downlink transmission during any TTI of therepetition window, where the repetition window includes a set of TTIs.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a series ofredundancy version (RV) indices for the repetition window based on theresource configuration, determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI may be based on the series of RV indices beginning at any TTIof the repetition window, and attempt to decode the grant-free downlinktransmission during a given TTI of the repetition window based on theone or more potential RV indices for the given TTI.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a series ofredundancy version (RV) indices for the repetition window based on theresource configuration, identify a HARQ process identification (ID) foreach TTI of the repetition window, where the HARQ process ID for eachTTI may be based on the series of RV indices beginning at any TTI of therepetition window, and combine logarithmic likelihood ratios (LLRs) ofthe grant-free downlink transmission for a given TTI with a previouslyreceived signal based on the HARQ process ID.

A method of wireless communication at a base station is described. Themethod may include transmitting, to a UE, a resource configuration fortransmission of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission, and transmitting the downlinktransmission, and transmitting the downlink transmission to the UE inaccordance with the resource configuration.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory.The instructions may be executable by the processor to cause theapparatus to transmit, to a UE, a resource configuration fortransmission of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission, and transmit the downlinktransmission to the UE in accordance with the resource configuration.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for transmitting, to a UE, aresource configuration for transmission of a downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the downlink transmission, andmeans for transmitting the downlink transmission to the UE in accordancewith the resource configuration.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission, and transmit thedownlink transmission to the UE in accordance with the resourceconfiguration.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting a firstrepetition of the downlink transmission during an initial TTI of therepetition window, the first repetition being associated with a firstredundancy version (RV) index, and transmit one or more additionalrepetitions of the downlink transmission during one or morecorresponding subsequent TTIs of the repetition window, each of the oneor more additional repetitions being associated with a respective RVindex.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the downlink transmission maybe a grant-free downlink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying a subset oftransmission time intervals (TTIs) within the repetition window duringwhich a first repetition of the grant-free downlink transmission may beallowed to be transmitted, where the repetition window includes thesubset of TTIs and at least one other TTI, transmit the first repetitionof the grant-free downlink transmission during a TTI of the subset ofTTIs, the first repetition being associated with a first redundancyversion (RV) index, and transmit one or more additional repetitions ofthe grant-free downlink transmission during one or more correspondingsubsequent TTIs of the at least one other TTI, each of the one or moreadditional repetitions being associated with a respective RV index.

A method of wireless communication at a UE is described. The method mayinclude means for receiving a resource configuration for reception of adownlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission, means for monitoring, in accordance with theresource configuration, one or more transmission time intervals (TTIs)of the repetition window for reception of the downlink transmission, andmeans for attempting to decode the downlink transmission during the oneor more TTIs of the repetition window based on the repetition windowsize.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the processor to cause the apparatusto means for receiving a resource configuration for reception of adownlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission, means for monitoring, in accordance with theresource configuration, one or more transmission time intervals (TTIs)of the repetition window for reception of the downlink transmission, andmeans for attempting to decode the downlink transmission during the oneor more TTIs of the repetition window based on the repetition windowsize.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for means for receiving a resourceconfiguration for reception of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission, means formonitoring, in accordance with the resource configuration, one or moretransmission time intervals (TTIs) of the repetition window forreception of the downlink transmission, and means for attempting todecode the downlink transmission during the one or more TTIs of therepetition window based on the repetition window size.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to means for receiving a resourceconfiguration for reception of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission, means formonitoring, in accordance with the resource configuration, one or moretransmission time intervals (TTIs) of the repetition window forreception of the downlink transmission, and means for attempting todecode the downlink transmission during the one or more TTIs of therepetition window based on the repetition window size.

A method of wireless communication at a base station is described. Themethod may include means for transmitting, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission and means fortransmitting the downlink transmission to the UE in accordance with theresource configuration.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory.The instructions may be executable by the processor to cause theapparatus to means for transmitting, to a UE, a resource configurationfor transmission of a downlink transmission within a repetition window,the resource configuration including an indicator of a repetition windowsize for the downlink transmission and means for transmitting thedownlink transmission to the UE in accordance with the resourceconfiguration.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for means for transmitting,to a UE, a resource configuration for transmission of a downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the downlinktransmission and means for transmitting the downlink transmission to theUE in accordance with the resource configuration.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to means for transmitting, to aUE, a resource configuration for transmission of a downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the downlink transmission andmeans for transmitting the downlink transmission to the UE in accordancewith the resource configuration.

A method of wireless communication at a UE, the code includinginstructions executable by a processor to is described. The method mayinclude receiving a resource configuration for reception of a downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the downlinktransmission, monitoring, in accordance with the resource configuration,one or more transmission time intervals (TTIs) of the repetition windowfor reception of the downlink transmission, and attempting to decode thedownlink transmission during the one or more TTIs of the repetitionwindow based on the repetition window size.

An apparatus for wireless communication at a UE, the code includinginstructions executable by a processor to is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe executable by the processor to cause the apparatus to receive aresource configuration for reception of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission, monitor, inaccordance with the resource configuration, one or more transmissiontime intervals (TTIs) of the repetition window for reception of thedownlink transmission, and attempt to decode the downlink transmissionduring the one or more TTIs of the repetition window based on therepetition window size.

Another apparatus for wireless communication at a UE, the code includinginstructions executable by a processor to is described. The apparatusmay include means for receiving a resource configuration for receptionof a downlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission, monitoring, in accordance with the resourceconfiguration, one or more transmission time intervals (TTIs) of therepetition window for reception of the downlink transmission, andattempting to decode the downlink transmission during the one or moreTTIs of the repetition window based on the repetition window size.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE, the code including instructions executable by aprocessor to is described. The code may include instructions executableby a processor to receive a resource configuration for reception of adownlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission, monitor, in accordance with the resourceconfiguration, one or more transmission time intervals (TTIs) of therepetition window for reception of the downlink transmission, andattempt to decode the downlink transmission during the one or more TTIsof the repetition window based on the repetition window size.

A method of wireless communication at a base station, the code includinginstructions executable by a processor to is described. The method mayinclude transmitting, to a UE, a resource configuration for transmissionof a downlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission and transmitting the downlink transmission to theUE in accordance with the resource configuration.

An apparatus for wireless communication at a base station, the codeincluding instructions executable by a processor to is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the processor to cause the apparatusto transmit, to a UE, a resource configuration for transmission of adownlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission and transmit the downlink transmission to the UEin accordance with the resource configuration.

Another apparatus for wireless communication at a base station, the codeincluding instructions executable by a processor to is described. Theapparatus may include means for transmitting, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission and transmittingthe downlink transmission to the UE in accordance with the resourceconfiguration.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station, the code including instructionsexecutable by a processor to is described. The code may includeinstructions executable by a processor to transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission and transmit thedownlink transmission to the UE in accordance with the resourceconfiguration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports downlink transmission in accordance with aspects of the presentdisclosure.

FIG. 2 illustrates an example of a wireless communications system thatsupports downlink transmission in accordance with aspects of the presentdisclosure.

FIGS. 3 through 5 illustrate example timing diagrams that supportgrant-free downlink transmission in accordance with aspects of thepresent disclosure.

FIG. 6 illustrates an example of a process flow that supports downlinktransmission in accordance with aspects of the present disclosure.

FIGS. 7 and 8 show block diagrams of a device that supports downlinktransmission in accordance with aspects of the present disclosure.

FIG. 9 illustrates a user equipment (UE) communications manager thatsupports downlink transmission in accordance with aspects of the presentdisclosure.

FIG. 10 illustrates a block diagram of a system including a UE thatsupports downlink transmission in accordance with aspects of the presentdisclosure.

FIGS. 11 and 12 show block diagrams of a device that supports downlinktransmission in accordance with aspects of the present disclosure.

FIG. 13 illustrates a base station communications manager that supportsdownlink transmission in accordance with aspects of the presentdisclosure.

FIG. 14 illustrates a block diagram of a system including a base stationthat supports downlink transmission in accordance with aspects of thepresent disclosure.

FIGS. 15 through 24 illustrate methods for grant-free downlinktransmission in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Some wireless communications systems may support grant-free uplinktransmissions (e.g., to reduce latency associated with schedulingrequest (SR) transmissions in grant-based uplink schemes). Similarly,grant-free transmission may be supported in the downlink (e.g., whichmay reduce control overhead associated with scheduling downlinktransmissions). For example, the reduced control overhead may benefitlow latency communication schemes which employ small packet sizes. Insome cases, grant-free transmissions may be associated with increasedcomplexity of decoding operations (e.g., because such transmissions arenot scheduled by a grant and may therefore be associated with somedegree of uncertainty in the decoding operation). Techniques arediscussed herein to address such complexities. In some cases, aspects ofthe techniques discussed may be applied to grant-based downlinktransmissions.

An example downlink transmission is provided in the context ofactivation-based transmissions. For activation-based transmissions, somedownlink parameters may be set via radio resource control (RRC)configuration, while other parameters may be given by an activatingdownlink control information (DCI) transmission. By way of example, ahybrid automatic repeat request (HARQ) process identification (ID) andredundancy version (RV) index for each transmission in theactivation-based scheme may be known (e.g., either based on DCI or as afunction of the transmission time interval (TTI) index). As an exampleof activation-based transmissions, repetition-based activated downlinktransmissions may employ a scheme in which the same transport block issent (e.g., multiple times) in each repetition window. Based on the DCIand RRC-configured parameters, the HARQ process ID and RV index for eachrepetition of the transport block in the repetition window may be known.Any re-transmissions (e.g., based on a negative acknowledgement by thereceiving device following the repetition window) may be transmittedusing a grant-based scheme. In some cases, activation-basedtransmissions may be repetition-based activated uplink transmissionsemploying a scheme in which the same transport block is sent in eachrepetition window.

Alternatively, in an activation-less grant-free downlink transmissionscheme, the UE may be configured with a set of parameters via RRC (e.g.,time/frequency resources, transport block size (TBS), RV sequence,repetition window size, etc.) without receiving an activating DCI. Thus,the UE may attempt to blindly decode repeated instances of a downlinktransmission over the given time/frequency resources (e.g., usingdifferent pairs of RV indices and HARQ process IDs) within a givenrepetition window. Aspects of the present disclosure relate totechniques for determining one or more potential RV indices and HARQprocess IDs for each TTI of the repetition window (e.g., rather thansearching across all possible pairings). Such techniques may benefit aUE in terms of power consumption, access latency, communicationthroughput, or the like.

In some cases, a wireless communications system may utilize anactivation-less grant-free transmission scheme (e.g., for uplink,downlink, sidelink transmissions), where a receiving device (e.g., a UE,a base station) may be configured with a set of parameters (e.g.,time/frequency resources, TBS sizes, RV sequence, repetition windowsize) without utilizing an activating DCI. Here, the receiving devicemay blindly decode repeated instances of the transmission over the giventime/frequency resources. Here, similar techniques for determining oneor more potential RV indices and HARQ process IDs for each TTI of therepetition window discussed herein may be applied to both uplink anddownlink transmissions.

Aspects of the disclosure are initially described in the context of awireless communications system. Aspects of the disclosure are thendescribed in the context of timing diagrams and a process flow. Aspectsof the disclosure are further illustrated by and described withreference to apparatus diagrams, system diagrams, and flowcharts thatrelate to grant-free downlink transmission.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a LTE network, an LTE-A network, an LTE-A Pro network, or anew radio (NR) network. In some cases, wireless communications system100 may support enhanced broadband communications, ultra-reliable (e.g.,mission critical) communications, low latency communications, orcommunications with low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation Node B orgiga-nodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions from a base station 105to a UE 115. Downlink transmissions may also be called forward linktransmissions while uplink transmissions may also be called reverse linktransmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, eachbase station 105 may provide communication coverage for a macro cell, asmall cell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap, and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different typesof base stations 105 provide coverage for various geographic coverageareas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples half-duplexcommunications may be performed at a reduced peak rate. Other powerconservation techniques for UEs 115 include entering a power saving“deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In some cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and a wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105, or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1 or otherinterface). Base stations 105 may communicate with one another overbackhaul links 134 (e.g., via an X2 or other interface) either directly(e.g., directly between base stations 105) or indirectly (e.g., via corenetwork 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one Packet Data Network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPMultimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 MHz to 300 GHz.Generally, the region from 300 MHz to 3 GHz is known as the ultra-highfrequency (UHF) region or decimeter band, since the wavelengths rangefrom approximately one decimeter to one meter in length. UHF waves maybe blocked or redirected by buildings and environmental features.However, the waves may penetrate structures sufficiently for a macrocell to provide service to UEs 115 located indoors. Transmission of UHFwaves may be associated with smaller antennas and shorter range (e.g.,less than 100 km) compared to transmission using the smaller frequenciesand longer waves of the high frequency (HF) or very high frequency (VHF)portion of the spectrum below 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that can tolerate interference from otherusers.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a CA configurationin conjunction with CCs operating in a licensed band (e.g., LAA).Operations in unlicensed spectrum may include downlink transmissions,uplink transmissions, peer-to-peer transmissions, or a combination ofthese. Duplexing in unlicensed spectrum may be based on frequencydivision duplexing (FDD), time division duplexing (TDD), or acombination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving devices are equipped with one ormore antennas. MIMO communications may employ multipath signalpropagation to increase the spectral efficiency by transmitting orreceiving multiple signals via different spatial layers, which may bereferred to as spatial multiplexing. The multiple signals may, forexample, be transmitted by the transmitting device via differentantennas or different combinations of antennas. Likewise, the multiplesignals may be received by the receiving device via different antennasor different combinations of antennas. Each of the multiple signals maybe referred to as a separate spatial stream, and may carry bitsassociated with the same data stream (e.g., the same codeword) ordifferent data streams. Different spatial layers may be associated withdifferent antenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO) where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO) where multiple spatial layers are transmitted to multipledevices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g., synchronizationsignals, reference signals, beam selection signals, or other controlsignals) may be transmitted by a base station 105 multiple times indifferent directions, which may include a signal being transmittedaccording to different beamforming weight sets associated with differentdirections of transmission. Transmissions in different beam directionsmay be used to identify (e.g., by the base station 105 or a receivingdevice, such as a UE 115) a beam direction for subsequent transmissionand/or reception by the base station 105. Some signals, such as datasignals associated with a particular receiving device, may betransmitted by a base station 105 in a single beam direction (e.g., adirection associated with the receiving device, such as a UE 115). Insome examples, the beam direction associated with transmissions along asingle beam direction may be determined based at least in in part on asignal that was transmitted in different beam directions. For example, aUE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions, and the UE 115 may report to thebase station 105 an indication of the signal it received with a highestsignal quality, or an otherwise acceptable signal quality. Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115), or transmitting a signal in asingle direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-basednetwork that operate according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may insome cases perform packet segmentation and reassembly to communicateover logical channels. A Medium Access Control (MAC) layer may performpriority handling and multiplexing of logical channels into transportchannels. The MAC layer may also use HARQ to provide retransmission atthe MAC layer to improve link efficiency. In the control plane, the RRCprotocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and a base station 105 or corenetwork 130 supporting radio bearers for user plane data. At thePhysical (PHY) layer, transport channels may be mapped to physicalchannels.

In some cases, UEs 115 and base stations 105 may support retransmissionsof data to increase the likelihood that data is received successfully.HARQ feedback is one technique of increasing the likelihood that data isreceived correctly over a communication link 125. HARQ may include acombination of error detection (e.g., using a cyclic redundancy check(CRC)), forward error correction (FEC), and retransmission (e.g.,automatic repeat request (ARQ)). HARQ may improve throughput at the MAClayer in poor radio conditions (e.g., signal-to-noise conditions). Insome cases, a wireless device may support same-slot HARQ feedback, wherethe device may provide HARQ feedback in a specific slot for datareceived in a previous symbol in the slot. In other cases, the devicemay provide HARQ feedback in a subsequent slot, or according to someother time interval. In some cases, multiple parallel HARQ processes(e.g., each associated with a respective HARQ process ID) may runconcurrently. Each HARQ process may be based on transmissions ofdifferent redundancy versions of a transport block (e.g., where thedifferent redundancy versions provide some level of diversity betweentransmissions, which diversity may be leveraged when combining theredundancy versions to decipher the transport block).

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases a subframe may be thesmallest scheduling unit of the wireless communications system 100, andmay be referred to as a TTI. In other cases, a smallest scheduling unitof the wireless communications system 100 may be shorter than a subframeor may be dynamically selected (e.g., in bursts of shortened TTIs(sTTIs) or in selected component carriers using sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an E-UTRA absolute radiofrequency channel number (EARFCN)), and may be positioned according to achannel raster for discovery by UEs 115. Carriers may be downlink oruplink (e.g., in an FDD mode), or be configured to carry downlink anduplink communications (e.g., in a TDD mode). In some examples, signalwaveforms transmitted over a carrier may be made up of multiplesub-carriers (e.g., using multi-carrier modulation (MCM) techniques suchas OFDM or DFT-s-OFDM).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR,etc.). For example, communications over a carrier may be organizedaccording to TTIs or slots, each of which may include user data as wellas control information or signaling to support decoding the user data. Acarrier may also include dedicated acquisition signaling (e.g.,synchronization signals or system information, etc.) and controlsignaling that coordinates operation for the carrier. In some examples(e.g., in a carrier aggregation configuration), a carrier may also haveacquisition signaling or control signaling that coordinates operationsfor other carriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth, or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs that can support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

Wireless communications system 100 may support communication with a UE115 on multiple cells or carriers, a feature which may be referred to ascarrier aggregation (CA) or multi-carrier operation. A UE 115 may beconfigured with multiple downlink CCs and one or more uplink CCsaccording to a carrier aggregation configuration. Carrier aggregationmay be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including wider carrier or frequency channel bandwidth, shortersymbol duration, shorter TTI duration, or modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (e.g., where more than one operator is allowed to usethe spectrum). An eCC characterized by wide carrier bandwidth mayinclude one or more segments that may be utilized by UEs 115 that arenot capable of monitoring the whole carrier bandwidth or are otherwiseconfigured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration may beassociated with increased spacing between adjacent subcarriers. Adevice, such as a UE 115 or base station 105, utilizing eCCs maytransmit wideband signals (e.g., according to frequency channel orcarrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symboldurations (e.g., 16.67 microseconds). A TTI in eCC may consist of one ormultiple symbol periods. In some cases, the TTI duration (that is, thenumber of symbol periods in a TTI) may be variable.

Wireless communications systems such as an NR system may utilize anycombination of licensed, shared, and unlicensed spectrum bands, amongothers. The flexibility of eCC symbol duration and subcarrier spacingmay allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossfrequency) and horizontal (e.g., across time) sharing of resources.

In accordance with the described techniques, a UE 115 may receive aresource configuration for reception of a downlink transmission (e.g., agrant-free downlink transmission) within a repetition window from a basestation 105. The resource configuration may, for example, include anindicator of a repetition window size for the downlink transmission. TheUE 115 may monitor, in accordance with the resource configuration, oneor more TTIs of the repetition window for reception of the downlinktransmission from the base station 105. The UE 115 may attempt to decodethe downlink transmission during the one or more TTIs of the repetitionwindow based at least in part on the repetition window size. Using thedescribed techniques, the UE 115 may efficiently determine one or moredecoding parameters for the downlink transmission, thereby providingbenefits in terms of latency reduction, power consumption, etc.

FIG. 2 illustrates an example of a wireless communications system 200that supports downlink transmission in accordance with various aspectsof the present disclosure. In some examples, wireless communicationssystem 200 may implement aspects of wireless communications system 100.Wireless communications system 200 includes base station 105-a, UE115-a, and UE 115-b, each of which may be an example of thecorresponding device described with reference to wireless communicationssystem 100.

As illustrated, base station 105-a may be in communication with UE 115-avia wireless link 205-a and may be in communication with UE 115-b viawireless link 205-b. In some examples, wireless link 205-a and/orwireless link 205-b may support grant-free downlink transmissions. Forexample, wireless link 205-a may support URLLC for UE 115-a. In somecases, base station 105-a may configure UE 115-a with one or moreparameters via higher layer signaling (e.g., RRC signaling). Forexample, the parameters may include one or more of time/frequencyresources associated with a given repetition window, a TBS fortransmissions within the repetition window, a number of TTIs in therepetition window (i.e., a repetition window size), a RV sequence, andthe like. Thus, UE 115-a may support activation-less, repetition-baseddownlink transmissions as described herein. Additionally oralternatively, base station 105-a may configure UE 115-b with one ormore parameters via higher layer signaling (e.g., RRC signaling). One ormore parameters for UE 115-b may be the same as the parameters for UE115-a, or each UE 115 may receive a unique set of parameters. By way ofexample, and as described further below, each of UE 115-a and UE 115-bmay indicate a maximum supported repetition window size (e.g., in acapability report), and the respective repetition window sizes for eachUE 115 may be based on the maximum supported repetition window sizes.

In some examples, information for multiple UEs 115 may be multiplexed onthe time/frequency resources associated with the repetition window forUE 115-a. Because a transmission intended for UE 115-a within therepetition window may not be triggered (e.g., by a DCI transmission), UE115-a may employ one or more of the techniques described herein todetermine a HARQ process ID, a RV index, etc. for a transmissionreceived within the repetition window.

As a first example, the repetition window size for UE 115-a may be oneTTI (i.e., repetition-based transmission may not be configured). In somecases of the first example, HARQ re-transmissions may therefore beenabled. In each TTI (e.g., or in the TTIs configured by the RRCsignaling), UE 115-a may attempt to blindly decode a transmission, suchas a physical downlink shared channel (PDSCH) transmission. For example,the blind decoding may be based on iteratively applying potentialpairings of HARQ process IDs and RV indices. That is, in each TTI UE115-a may attempt to decode the PDSCH transmission assuming it is afirst transmission (i.e., having a first RV index in the RV sequenceconfigured by the RRC signaling and a HARQ process ID given by the TTIindex). If this decoding attempt fails, UE 115-a may try decoding thePDSCH transmission assuming it is a subsequent transmission (i.e.,having a subsequent RV index in the RV sequence configured by the RRCsignaling). Thus, UE 115-a may attempt to combine the logarithmiclikelihood ratios (LLRs) for the PDSCH transmission with any pendingHARQ processes received some defined number of TTIs prior to the currentTTI (e.g., which may be based on some predetermined rule or negotiatedbetween UE 115-a and base station 105-a). By way of example, UE 115-amay expect to receive any retransmissions of a transport block receivedin a prior TTI in a given TTI that occurs after some predetermined(e.g., configured) time has elapsed. Thus, upon failing to decode thePDSCH transmission using a first RV index hypothesis (e.g., based on theRV sequence received in the RRC configuration), the UE 115-a may apply(e.g., iteratively) other candidate RV indices (e.g., and HARQ processIDs) based on a given periodicity associated with the HARQretransmission process. Alternatively, the HARQ re-transmissions may besent with a grant (e.g., a DCI transmission), which may address variouscomplications of the scheme described herein. However, aspects of thescheme described herein may apply to repetition-based transmissionschemes, as discussed with reference to FIGS. 3, 4, and 5.

FIG. 3 illustrates an example of a timing diagram 300 that supportsdownlink transmission in accordance with various aspects of the presentdisclosure. In some examples, timing diagram 300 may implement aspectsof wireless communication system 100.

Timing diagram 300 contains a plurality of TTIs 310, some of which maybe grouped into repetition windows 305. In the present example, eachrepetition window 305 contains four (4) TTIs 310, though it is to beunderstood that other numbers of TTIs 310 may be included in eachrepetition window 305 (e.g., based on some UE-indicated capability)without deviating from the scope of the present disclosure. Similarly,while repetition window 305-a and repetition window 305-b areillustrated as being adjacent in time, it is to be understood that insome cases, the repetition windows 305 may occur with a givenperiodicity (e.g., one or more TTIs 310 may separate repetition window305-a and repetition window 305-b) without deviating from the scope ofthe present disclosure.

Within repetition window 305-a, the same transport block may be sentmultiple times (e.g., with different RVs). Repetition window 305-a maythus employ a RV sequence (e.g., configured via RRC signaling) for eachTTI 310. By way of example, the RV sequence may be [0, 2, 3, 1] suchthat RV 0 is sent in TTI 310-a, RV 2 is sent in TTI 310-b, RV 3 is sentin TTI 310-c, and RV 1 is sent in TTI 310-d. In the case that repetitionwindow 305-a contains more than four (4) TTIs 310, the RV sequence (or aportion thereof) may repeat, Thus, a UE 115 monitoring resources ofrepetition window 305-a may only expect to receive a new transport block(e.g., RV 0) during TTI 310-a.

In some cases, the TTIs 310 may be transmitted within a grant-freedownlink transmission. The UE 115 may therefore infer both the HARQprocess ID (e.g., based on the TTI index of TTI 310-a) and RV index(e.g., based on the RV sequence applied to the TTIs 310 of repetitionwindow 305). Here, the index of the first TTI 310-a may indicate (e.g.,implicitly) a HARQ process ID. For example, a receiver (e.g., UE 115,base station 105) may perform blind decodes based on the RV sequenceapplied to the TTIs 310 and then determine the index of the first TTI310-a. Based on the index of TTI 310-a, the receiver may then determinethe HARQ process ID. Accordingly, the number of blind decoding attemptsfor each TTI 310 may be reduced compared to the search described withreference to FIG. 2 (e.g., only one decoding hypothesis may be attemptedfor each TTI 310). In some other cases, the TTIs 310 may be transmittedwithin a grant-based downlink transmission. The receiver may know (e.g.,based on DCI signaling from a base station) the HARQ process ID and RVindex.

FIG. 4 illustrates an example of a timing diagram 400 that supportsdownlink transmission in accordance with various aspects of the presentdisclosure. In some examples, timing diagram 400 may implement aspectsof wireless communication system 100. Timing diagram 400 contains aplurality of TTIs 410, some of which may be grouped into repetitionwindow 405. In the present example, repetition window 405 contains six(6) TTIs 410, though it is to be understood that other numbers of TTIs410 may be included in repetition window 405 (e.g., based on someUE-indicated capability) without deviating from the scope of the presentdisclosure.

Within repetition window 405, the same transport block may be sentmultiple times (e.g., with different RVs). In accordance with thepresent disclosure, a subset of the TTIs 410 in repetition window 405may contain a new transport block (e.g., having RV 0). By way ofexample, the new transport block may be contained in TTI 410-a or TTI410-b (e.g., but not TTI 410-c). Thus, a UE 115 may attempt to blindlydecode a PDSCH transmission in TTI 410-a using a first RV index in a RVsequence received via RRC configuration and a HARQ process ID given byan index of TTI 410-a. If the decoding attempt is successful, the UE 115may subsequently attempt to decode a second repetition of the transportblock (e.g., having a second RV index in the RV sequence received viaRRC signaling) in a second TTI 410 of timing alignment 415-a.Alternatively (e.g., if the decoding attempt for the first RV index atTTI 410-a and the decoding attempt for the second RV index at the secondTTI 410 of repetition window 405), the UE 115 may attempt to blindlydecode the PDSCH transmission in TTI 410-b using the first RV index(e.g., assuming that the PDSCH transmission is sent according to timingalignment 415-b). If this decoding attempt fails, the UE 115 may attemptto blindly decode the PDSCH transmission in TTI 410-b using the third RVindex in the RV sequence (e.g., assuming that the PDSCH transmission issent according to timing alignment 415-a despite the previously faileddecoding attempts, which may be due to interference, lack of signal,etc.).

FIG. 5 illustrates an example of a timing diagram 500 that supportsdownlink transmission in accordance with various aspects of the presentdisclosure. In some examples, timing diagram 500 may implement aspectsof wireless communication system 100. Timing diagram 500 contains aplurality of TTIs 510, some of which may be grouped into repetitionwindow 505. In the present example, repetition window 505 contains six(6) TTIs 510, though it is to be understood that other numbers of TTIs510 may be included in repetition window 505 (e.g., based on someUE-indicated capability) without deviating from the scope of the presentdisclosure.

Within repetition window 405, the same transport block may be sentmultiple times (e.g., with different RVs). In accordance with thepresent disclosure, each TTI 510 in repetition window 505 may contain anew transport block (e.g., having RV 0). By way of example, the newtransport block may be contained in TTI 510-a (e.g., as illustrated bytiming alignment 515-a), TTI 510-b (e.g., as illustrated by timingalignment 515-b), TTI 510-c (e.g., as illustrated by timing alignment515-c), etc. Thus, a UE 115 may attempt to blindly decode a PDSCHtransmission in TTI 510-a using a first RV index in a RV sequencereceived via RRC configuration and a HARQ process ID given by an indexof TTI 510-a. If the decoding attempt is successful, the UE 115 maysubsequently attempt to decode a second transport block (e.g.,corresponding to timing alignment 515-b or timing alignment 515-c) inTTI 510-b.

Alternatively (e.g., if the decoding attempt for the first RV index atTTI 510-a is unsuccessful), the UE 115 may attempt to decode the PDSCHtransmission in TTI 510-b using the first RV index (e.g., assuming thatthe PDSCH transmission is sent according to timing alignment 515-b) andthe HARQ process ID corresponding to TTI 510-b. If this decoding attemptfails, the UE 115 may attempt to blindly decode the PDSCH transmissionin TTI 510-b using the second RV index in the RV sequence (e.g.,assuming that the PDSCH transmission is sent according to timingalignment 515-b) and the HARQ process ID corresponding to TTI 510-a.Similarly, if these decoding attempts fail, the UE 115 may attempt todecode the PDSCH transmission in TTI 510-c according to timing alignment515-c (e.g., using the first RV index and the HARQ process IDcorresponding to TTI 510-c), followed by timing alignment 515-b (e.g.,using the second RV index and the HARQ process ID corresponding to TTI510-b), followed by timing alignment 515-a (e.g., using the third RVindex and the HARQ process ID corresponding to TTI 510-c). The decodingattempts may be performed in a different order (e.g., the UE 115 mayattempt to decode the PDSCH transmission in TTI 510-c according totiming alignment 515-a before attempting to decode the PDSCHtransmission according to timing alignment 515-b) without deviating fromthe scope of the present disclosure.

Thus, in some cases, as the size of repetition window 505 increases, theUE 115 may experience a corresponding increase in blind decodingattempts (e.g., for TTIs 510 later in the repetition window 505) basedon the additional potential timing alignment 515 introduced at each TTI510. Accordingly, there may in some cases be a repetition window 505threshold (e.g., above which grant-based downlink transmissions may beperformed and below which grant-free downlink transmissions may beperformed). As discussed herein, the length of the repetition window 505may in some cases be an example of a UE 115 capability (e.g., which maybe conveyed via RRC signaling or otherwise communicated to a basestation 105).

FIG. 6 illustrates an example of a process flow 600 that supportsdownlink transmission in accordance with various aspects of the presentdisclosure. In some examples, process flow 600 may implement aspects ofwireless communication system 100. For example, process flow 600includes base station 105-b and UE 115-c, each of which may be anexample of the corresponding devices described with reference to FIGS. 1and 2.

At 605, base station 105-b may transmit (e.g., and UE 115-c may receive)a resource configuration for reception of a grant-free downlinktransmission within a repetition window. For example, the resourceconfiguration may include an indicator of a repetition window size forthe grant-free downlink transmission. Additionally or alternatively, theresource configuration may include a series of RV indices (i.e., a RVsequence), a TBS, time/frequency resources associated with therepetition window, etc. In some cases, the resource configuration may besent via RRC signaling. In some examples, the repetition window size maybe based at least in part on a capability of UE 115-c (e.g., which maybe communicated to base station 105-b prior to 605). For example, thecapability may indicate a maximum repetition window size supported by UE115-c, a timing within the repetition window for which UE 115-c supportstransmission of a first repetition of the grant-free downlinktransmission (e.g., where possible different timings for the firstrepetition are discussed with reference to FIG. 3, FIG. 4, and FIG. 5),or combinations of the same.

At 610, UE 115-c may monitor, in accordance with the resourceconfiguration, one or more TTIs of the repetition window for receptionof the grant-free downlink transmission. For example, UE 115-c maymonitor for a first repetition of the grant-free downlink transmissionin an initial TTI of the repetition window (e.g., as described withreference to FIG. 3). Additionally or alternatively, UE 115-c mayidentify, based at least in part on the resource configuration, a subsetof TTIs within the repetition window during which the grant-freedownlink transmission is allowed to be transmitted and monitor for afirst repetition of the grant-free downlink transmission during at leastone TTI of the subset of TTIs (e.g., as described with reference to FIG.4). Additionally or alternatively, UE 115 c may monitor for a firstrepetition of the grant-free downlink transmission during any TTI of therepetition window (e.g., as described with reference to FIG. 5).

At 615, UE 115-c may attempt to decode the grant-free downlinktransmission during the one or more TTIs of the repetition window basedat least in part on the repetition window size. For example, UE 115-cmay identify a potential RV index and a corresponding HARQ process IDfor the grant-free downlink transmission, where each decoding attempt isbased on a unique pair of potential RV index and corresponding HARQprocess ID. In some cases, UE 115-c may determine a TTI index for eachof the one or more TTIs of the repetition window, where thecorresponding HARQ process ID for a given TTI is based at least in parton the TTI index for the given TTI. In some cases, UE 115-c may identifya series of RV indices for the repetition window based at least in parton the resource configuration, each RV index of the series of RV indicesassociated with a respective TTI of the repetition window and attempt todecode the grant-free downlink transmission during a given TTI of therepetition window based at least in part on the RV index associated withthe given TTI (e.g., as described with reference to FIG. 3).

Additionally or alternatively, at 615, UE 115-c may identify a series ofRV indices for the repetition window based at least in part on theresource configuration, determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based at least in part on the series of RV indices beginningat a respective TTI of the subset of TTIs, and attempt to decode thegrant-free downlink transmission during a given TTI of the repetitionwindow based at least in part on the one or more potential RV indicesfor the given TTI (e.g., as described with reference to FIG. 4). Forexample, UE 115-c may fail to decode the first repetition of thegrant-free downlink transmission during an initial TTI of the subset ofTTIs and attempt to decode the first repetition of the grant-freedownlink transmission during an immediately subsequent TTI of the subsetof TTIs based at least in part on failing to decode the first repetitionduring the initial TTI of the subset of TTIs (e.g., as described withreference to FIG. 4).

Additionally or alternatively, at 615, UE 115-c may identifying a seriesof RV indices for the repetition window based at least in part on theresource configuration, determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based at least in part on the series of RV indices beginningat any TTI of the repetition window, and attempt to decode thegrant-free downlink transmission during a given TTI of the repetitionwindow based at least in part on the one or more potential RV indicesfor the given TTI (e.g., as described with reference to FIG. 5). Forexample, UE 115-c may determine that a first decoding hypothesiscorresponding to decoding the first repetition of the grant-freedownlink transmission during a given TTI of the repetition window hasfailed and attempt to decode a second repetition of the grant-freedownlink transmission using a second decoding hypothesis during thegiven TTI of the repetition window based at least in part on thedetermination that the first decoding hypothesis has failed (e.g., asdescribed with reference to FIG. 5). In some cases, UE 115-c may attemptto decode the first repetition of the grant-free downlink transmissionusing an additional decoding hypothesis during a subsequent TTI of therepetition window based at least in part on the determination that thefirst decoding hypothesis has failed (e.g., as described with referenceto FIG. 5).

At 620, base station 105-b may transmit the grant-free downlinktransmission to the UE in accordance with the resource configuration. Insome cases, base station 105-b may transmit a first repetition of thegrant-free downlink transmission during an initial TTI of the repetitionwindow, the first repetition being associated with a first RV index andtransmit one or more additional repetitions of the grant-free downlinktransmission during one or more corresponding subsequent TTIs of therepetition window, each of the one or more additional repetitions beingassociated with a respective RV index (e.g., as described with referenceto FIG. 3). In some cases, base station 105-b may identify a subset ofTTIs within the repetition window during which a first repetition of thegrant-free downlink transmission is allowed to be transmitted, where therepetition window includes the subset of TTIs and at least one otherTTI, transmit the first repetition of the grant-free downlinktransmission during a TTI of the subset of TTIs, the first repetitionbeing associated with a first RV index, and transmit one or moreadditional repetitions of the grant-free downlink transmission duringone or more corresponding subsequent TTIs of the at least one other TTI,each of the one or more additional repetitions being associated with arespective RV index (e.g., as described with reference to FIG. 4). Insome cases, base station 105-b may transmit a first repetition of thegrant-free downlink transmission during any TTI of the repetitionwindow, the first repetition being associated with a first RV index andtransmit one or more additional repetitions of the grant-free downlinktransmission during one or more corresponding subsequent TTIs of therepetition window, each of the one or more additional repetitions beingassociated with a respective RV index (e.g., as described with referenceto FIG. 5). Thus, in some cases the operations at 620 (i.e., thetransmission(s) from base station 105-b) may overlap in time with theoperations at 615 (i.e., the decoding attempt(s) at UE 115-c).

At 625, UE 115-c may optionally transmit (e.g., and base station 105-bmay receive) an indication (e.g., an acknowledgment (ACK)) that thegrant-free downlink transmission was successfully decoded (e.g., after aconclusion of the repetition window).

FIG. 7 shows a block diagram 700 of a wireless device 705 that supportsdownlink transmission in accordance with aspects of the presentdisclosure. Wireless device 705 may be an example of aspects of a UE 115as described herein. Wireless device 705 may include receiver 710, UEcommunications manager 715, and transmitter 720. Wireless device 705 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to grant-freedownlink transmission, etc.). Information may be passed on to othercomponents of the device. The receiver 710 may be an example of aspectsof the transceiver 1035 described with reference to FIG. 10. Thereceiver 710 may utilize a single antenna or a set of antennas.

UE communications manager 715 may be an example of aspects of the UEcommunications manager 1015 described with reference to FIG. 10. UEcommunications manager 715 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the UE communicationsmanager 715 and/or at least some of its various sub-components may beexecuted by a general-purpose processor, a digital signal processor(DSP), an application-specific integrated circuit (ASIC), anfield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure.

UE communications manager 715 and/or at least some of its varioussub-components may be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations by one or more physical devices. In someexamples, UE communications manager 715 and/or at least some of itsvarious sub-components may be a separate and distinct component inaccordance with various aspects of the present disclosure. In otherexamples, UE communications manager 715 and/or at least some of itsvarious sub-components may be combined with one or more other hardwarecomponents, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with various aspects of the present disclosure.

UE communications manager 715 may receive a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission. UE communications manager 715 maymonitor, in accordance with the resource configuration, one or more TTIsof the repetition window for reception of the downlink transmission. UEcommunications manager 715 may attempt to decode the downlinktransmission during the one or more TTIs of the repetition window basedon the repetition window size.

Transmitter 720 may transmit signals generated by other components ofthe device. In some examples, the transmitter 720 may be collocated witha receiver 710 in a transceiver module. For example, the transmitter 720may be an example of aspects of the transceiver 1035 described withreference to FIG. 10. The transmitter 720 may utilize a single antennaor a set of antennas.

FIG. 8 shows a block diagram 800 of a wireless device 805 that supportsdownlink transmission in accordance with aspects of the presentdisclosure. Wireless device 805 may be an example of aspects of awireless device 705 or a UE 115 as described with reference to FIG. 7.Wireless device 805 may include receiver 810, UE communications manager815, and transmitter 820. Wireless device 805 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses). UE communications manager 815 maybe an example of aspects of the UE communications manager 1015 describedwith reference to FIG. 10. UE communications manager 815 may alsoinclude configuration manager 825, resource monitoring controller 830,and decoding manager 835.

Receiver 810 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to grant-freedownlink transmission, etc.). Information may be passed on to othercomponents of the device. The receiver 810 may be an example of aspectsof the transceiver 1035 described with reference to FIG. 10. Thereceiver 810 may utilize a single antenna or a set of antennas.

Configuration manager 825 may receive a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission. In some cases, the resourceconfiguration is received via RRC signaling. In some cases, the resourceconfiguration includes a series of RV indices for repeated transmissionsof the downlink transmission within the repetition window, a TBS, anindication of time/frequency resources, or combinations thereof.

Resource monitoring controller 830 may monitor, in accordance with theresource configuration, one or more TTIs of the repetition window forreception of the downlink transmission. In some cases, monitoring theone or more TTIs of the repetition window for reception of the downlinktransmission includes identifying, based on the resource configuration,a subset of TTIs within the repetition window during which a firstrepetition of the downlink transmission, which may be a grant-freedownlink transmission, is allowed to be transmitted, where therepetition window includes the subset of TTIs and at least one otherTTI. For example, resource monitoring controller 830 may monitor for afirst repetition of the grant-free downlink transmission during at leastone TTI of the subset of TTIs. In some cases, monitoring the one or moreTTIs of the repetition window for reception of the grant-free downlinktransmission includes monitoring for a first repetition of thegrant-free downlink transmission during any TTI of the repetitionwindow, where the repetition window includes multiple TTIs. In somecases, monitoring the one or more TTIs of the repetition window forreception of the grant-free downlink transmission includes monitoringfor a first repetition of the grant-free downlink transmission in aninitial TTI of the repetition window, where the repetition window sizeis greater than one TTI.

Decoding manager 835 may attempt to decode the downlink transmissionduring the one or more TTIs of the repetition window based on therepetition window size. In some cases, attempting to decode the downlinktransmission, which may be a grant-free downlink transmission, includesidentifying a series of RV indices for the repetition window based onthe resource configuration. In some cases, each RV index of the seriesof RV indices is associated with a respective TTI of the repetitionwindow. In some cases, attempting to decode the grant-free downlinktransmission includes identifying a potential RV index and acorresponding HARQ process ID for the grant-free downlink transmission,where each decoding attempt is based on a unique pair of potential RVindex and corresponding HARQ process ID. In some cases, identifying thepotential RV index and the corresponding HARQ process ID for thegrant-free downlink transmission includes determining a TTI index foreach of the one or more TTIs of the repetition window, where thecorresponding HARQ process ID for a given TTI is based on the TTI indexfor the given TTI.

Decoding manager 835 may determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based on the series of RV indices beginning at a respectiveTTI of the subset of TTIs. Decoding manager 835 may determine one ormore potential RV indices for each TTI of the repetition window, whereeach potential RV index for each TTI is based on the series of RVindices beginning at any TTI of the repetition window. Decoding manager835 may attempt to decode the grant-free downlink transmission during agiven TTI of the repetition window based on the one or more potential RVindices for the given TTI.

Decoding manager 835 may determine that a first decoding hypothesiscorresponding to decoding the first repetition of the downlinktransmission during a given TTI of the repetition window has failed.Decoding manager 835 may attempt to decode a second repetition of thedownlink transmission, which may be a grant-free downlink transmission,using a second decoding hypothesis during the given TTI of therepetition window based on the determination that the first decodinghypothesis has failed. Decoding manager 835 may attempt to decode thefirst repetition of the grant-free downlink transmission using anadditional decoding hypothesis during a subsequent TTI of the repetitionwindow based on the determination that the first decoding hypothesis hasfailed. Decoding manager 835 may attempt to decode the first repetitionof the grant-free downlink transmission during an immediately subsequentTTI of the subset of TTIs based on failing to decode the firstrepetition during the initial TTI of the subset of TTIs. Decodingmanager 835 may transmit an indication that the downlink transmissionwas successfully decoded.

Decoding manager 835 may identify a series of RV indices for therepetition window based at least in part on the resource configuration.Decoding manager 835 may identify a HARQ process ID for each TTI of therepetition window, where the HARQ process ID for each TTI is based atleast in part on the series of RV indices beginning at a respective TTIof the subset of TTIs. Decoding manager 835 may combine LLRs of thegrant-free downlink transmission for a given TTI with a previouslyreceived signal based at least in part on the HARQ process ID. Decodingmanager 835 may identify a HARQ process ID for each TTI of therepetition window, where the HARQ process ID for each TTI is based atleast in part on the series of RV indices beginning at any TTI of therepetition window. Decoding manager 835 may combine LLRs of thegrant-free downlink transmission for a given TTI with a previouslyreceived signal based at least in part on the HARQ process ID.

Transmitter 820 may transmit signals generated by other components ofthe device. In some examples, the transmitter 820 may be collocated witha receiver 810 in a transceiver module. For example, the transmitter 820may be an example of aspects of the transceiver 1035 described withreference to FIG. 10. The transmitter 820 may utilize a single antennaor a set of antennas.

FIG. 9 shows a block diagram 900 of a UE communications manager 915 thatsupports downlink transmission in accordance with aspects of the presentdisclosure. The UE communications manager 915 may be an example ofaspects of a UE communications manager 715, a UE communications manager815, or a UE communications manager 1015 described with reference toFIGS. 7, 8, and 10. The UE communications manager 915 may includeconfiguration manager 920, resource monitoring controller 925, decodingmanager 930, and capability manager 935. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

Configuration manager 920 may receive a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission. In some cases, the resourceconfiguration is received via RRC signaling. In some cases, the resourceconfiguration includes a series of RV indices for repeated transmissionsof the downlink transmission within the repetition window, a TBS, anindication of time/frequency resources, or combinations thereof.

Resource monitoring controller 925 may monitor, in accordance with theresource configuration, one or more TTIs of the repetition window forreception of the downlink transmission. In some cases, monitoring theone or more TTIs of the repetition window for reception of the downlinktransmission, which may be a grant-free downlink transmission, includesidentifying, based on the resource configuration, a subset of TTIswithin the repetition window during which a first repetition of thegrant-free downlink transmission is allowed to be transmitted, where therepetition window includes the subset of TTIs and at least one otherTTI. For example, resource monitoring controller 925 may monitor for afirst repetition of the grant-free downlink transmission during at leastone TTI of the subset of TTIs. In some cases, monitoring the one or moreTTIs of the repetition window for reception of the grant-free downlinktransmission includes monitoring for a first repetition of thegrant-free downlink transmission during any TTI of the repetitionwindow, where the repetition window includes multiple TTIs. In somecases, monitoring the one or more TTIs of the repetition window forreception of the downlink transmission includes monitoring for a firstrepetition of the downlink transmission in an initial ITT of therepetition window, where the repetition window size is greater than oneTTI.

Decoding manager 930 may attempt to decode the downlink transmissionduring the one or more TTIs of the repetition window based on therepetition window size. In some cases, attempting to decode the downlinktransmission, which may be a grant-free downlink transmission, includesidentifying a series of RV indices for the repetition window based onthe resource configuration. In some cases, each RV index of the seriesof RV indices is associated with a respective TTI of the repetitionwindow. In some cases, attempting to decode the grant-free downlinktransmission includes identifying a potential RV index and acorresponding HARQ process ID for the grant-free downlink transmission,where each decoding attempt is based on a unique pair of potential RVindex and corresponding HARQ process ID. In some cases, identifying thepotential RV index and the corresponding HARQ process ID for thegrant-free downlink transmission includes determining a TTI index foreach of the one or more TTIs of the repetition window, where thecorresponding HARQ process ID for a given TTI is based on the TTI indexfor the given TTI.

Decoding manager 930 may determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based on the series of RV indices beginning at a respectiveTTI of the subset of TTIs. Decoding manager 930 may determine one ormore potential RV indices for each TTI of the repetition window, whereeach potential RV index for each TTI is based on the series of RVindices beginning at any TTI of the repetition window. Decoding manager930 may attempt to decode the grant-free downlink transmission during agiven TTI of the repetition window based on the one or more potential RVindices for the given TTI.

Decoding manager 930 may determine that a first decoding hypothesiscorresponding to decoding the first repetition of the grant-freedownlink transmission during a given TTI of the repetition window hasfailed. Decoding manager 930 may attempt to decode a second repetitionof the grant-free downlink transmission using a second decodinghypothesis during the given TTI of the repetition window based on thedetermination that the first decoding hypothesis has failed. Decodingmanager 930 may attempt to decode the first repetition of the grant-freedownlink transmission using an additional decoding hypothesis during asubsequent TTI of the repetition window based on the determination thatthe first decoding hypothesis has failed. Decoding manager 930 mayattempt to decode the first repetition of the grant-free downlinktransmission during an immediately subsequent TTI of the subset of TTIsbased on failing to decode the first repetition during the initial TTIof the subset of TTIs. Decoding manager 930 may transmit an indicationthat the downlink transmission was successfully decoded.

Decoding manager 930 may identify a series of RV indices for therepetition window based at least in part on the resource configuration.Decoding manager 930 may identify a HARQ process ID for each TTI of therepetition window, where the HARQ process ID for each TTI is based atleast in part on the series of RV indices beginning at a respective TTIof the subset of TTIs. Decoding manager 930 may combine LLRs of thegrant-free downlink transmission for a given TTI with a previouslyreceived signal based at least in part on the HARQ process ID. Decodingmanager 930 may identify a HARQ process ID for each TTI of therepetition window, where the HARQ process ID for each TTI is based atleast in part on the series of RV indices beginning at any TTI of therepetition window. Decoding manager 930 may combine LLRs of thegrant-free downlink transmission for a given TTI with a previouslyreceived signal based at least in part on the HARQ process ID.

Capability manager 935 may transmit an indication of a capability of theUE, the capability indicating a maximum repetition window size supportedby the UE, a timing within the repetition window for which the UEsupports transmission of a first repetition of the grant-free downlinktransmission, or combinations of the same.

FIG. 10 shows a diagram of a system 1000 including a device 1005 thatsupports downlink transmission in accordance with aspects of the presentdisclosure. Device 1005 may be an example of or include the componentsof wireless device 705, wireless device 805, or a UE 115 as describedherein, e.g., with reference to FIGS. 7 and 8. Device 1005 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, including UEcommunications manager 1015, processor 1020, memory 1025, software 1030,transceiver 1035, antenna 1040, and I/O controller 1045. Thesecomponents may be in electronic communication via one or more buses(e.g., bus 1010). Device 1005 may communicate wirelessly with one ormore base stations 105.

Processor 1020 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a central processing unit (CPU), amicrocontroller, an ASIC, an FPGA, a programmable logic device, adiscrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, processor 1020may be configured to operate a memory array using a memory controller.In other cases, a memory controller may be integrated into processor1020. Processor 1020 may be configured to execute computer-readableinstructions stored in a memory to perform various functions (e.g.,functions or tasks supporting grant-free downlink transmission).

Memory 1025 may include random access memory (RAM) and read only memory(ROM). The memory 1025 may store computer-readable, computer-executablesoftware 1030 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 1025 may contain, among other things, a basic input/outputsystem (BIOS) which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Software 1030 may include code to implement aspects of the presentdisclosure, including code to support downlink transmission. Software1030 may be stored in a non-transitory computer-readable medium such assystem memory or other memory. In some cases, the software 1030 may notbe directly executable by the processor but may cause a computer (e.g.,when compiled and executed) to perform functions described herein.

Transceiver 1035 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described herein. For example, thetransceiver 1035 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1035 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas. In some cases, thewireless device may include a single antenna 1040. However, in somecases the device may have more than one antenna 1040, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

I/O controller 1045 may manage input and output signals for device 1005.I/O controller 1045 may also manage peripherals not integrated intodevice 1005. In some cases, I/O controller 1045 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 1045 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 1045 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 1045 may be implemented as part of aprocessor. In some cases, a user may interact with device 1005 via I/Ocontroller 1045 or via hardware components controlled by I/O controller1045.

FIG. 11 shows a block diagram 1100 of a wireless device 1105 thatsupports downlink transmission in accordance with aspects of the presentdisclosure. Wireless device 1105 may be an example of aspects of a basestation 105 as described herein. Wireless device 1105 may includereceiver 1110, base station communications manager 1115, and transmitter1120. Wireless device 1105 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 1110 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to grant-freedownlink transmission, etc.). Information may be passed on to othercomponents of the device. The receiver 1110 may be an example of aspectsof the transceiver 1435 described with reference to FIG. 14. Thereceiver 1110 may utilize a single antenna or a set of antennas.

Base station communications manager 1115 may be an example of aspects ofthe base station communications manager 1415 described with reference toFIG. 14. Base station communications manager 1115 and/or at least someof its various sub-components may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions of thebase station communications manager 1115 and/or at least some of itsvarious sub-components may be executed by a general-purpose processor, aDSP, an ASIC, an FPGA or other programmable logic device, discrete gateor transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described in the presentdisclosure.

The base station communications manager 1115 and/or at least some of itsvarious sub-components may be physically located at various positions,including being distributed such that portions of functions areimplemented at different physical locations by one or more physicaldevices. In some examples, base station communications manager 1115and/or at least some of its various sub-components may be a separate anddistinct component in accordance with various aspects of the presentdisclosure. In other examples, base station communications manager 1115and/or at least some of its various sub-components may be combined withone or more other hardware components, including but not limited to anI/O component, a transceiver, a network server, another computingdevice, one or more other components described in the presentdisclosure, or a combination thereof in accordance with various aspectsof the present disclosure.

Base station communications manager 1115 may transmit, to a UE, aresource configuration for transmission of a downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the downlink transmission.Base station communications manager 1115 may transmit the downlinktransmission to the UE in accordance with the resource configuration.

Transmitter 1120 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1120 may be collocatedwith a receiver 1110 in a transceiver module. For example, thetransmitter 1120 may be an example of aspects of the transceiver 1435described with reference to FIG. 14. The transmitter 1120 may utilize asingle antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a wireless device 1205 thatsupports downlink transmission in accordance with aspects of the presentdisclosure. Wireless device 1205 may be an example of aspects of awireless device 1105 or a base station 105 as described with referenceto FIG. 11. Wireless device 1205 may include receiver 1210, base stationcommunications manager 1215, and transmitter 1220. Wireless device 1205may also include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses). Basestation communications manager 1215 may be an example of aspects of thebase station communications manager 1415 described with reference toFIG. 14. Base station communications manager 1215 may also includeconfiguration controller 1225 and downlink transmission manager 1230.

Receiver 1210 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to grant-freedownlink transmission, etc.). Information may be passed on to othercomponents of the device. The receiver 1210 may be an example of aspectsof the transceiver 1435 described with reference to FIG. 14. Thereceiver 1210 may utilize a single antenna or a set of antennas.

Configuration controller 1225 may transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission. In some cases,the resource configuration is transmitted via RRC signaling, theresource configuration further including a series of RV indices for therepetition window.

Downlink transmission manager 1230 may transmit the downlinktransmission to the UE in accordance with the resource configuration.For example, downlink transmission manager 1230 may transmit one or moreadditional repetitions of the downlink transmission during one or morecorresponding subsequent TTIs of the repetition window, each of the oneor more additional repetitions being associated with a respective RVindex. As another example, downlink transmission manager 1230 maytransmit the first repetition of the downlink transmission, which may bea grant-free downlink transmission, during a TTI of the subset of TTIs,the first repetition being associated with a first RV index. Downlinktransmission manager 1230 may transmit one or more additionalrepetitions of the grant-free downlink transmission during one or morecorresponding subsequent TTIs of the at least one other TTI, each of theone or more additional repetitions being associated with a respective RVindex. Downlink transmission manager 1230 may receive, from the UE, anindication of a successful decoding of the downlink transmission.

In some cases, transmitting the downlink transmission to the UE includestransmitting a first repetition of the downlink transmission during aninitial TTI of the repetition window, the first repetition beingassociated with a first RV index. In some cases, transmitting thedownlink transmission, which may be a grant-free downlink transmission,to the UE includes identifying a subset of TTIs within the repetitionwindow during which a first repetition of the grant-free downlinktransmission is allowed to be transmitted, where the repetition windowincludes the subset of TTIs and at least one other TTI. In some cases,transmitting the grant-free downlink transmission to the UE includestransmitting a first repetition of the grant-free downlink transmissionduring any TTI of the repetition window, the first repetition beingassociated with a first RV index.

Transmitter 1220 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1220 may be collocatedwith a receiver 1210 in a transceiver module. For example, thetransmitter 1220 may be an example of aspects of the transceiver 1435described with reference to FIG. 14. The transmitter 1220 may utilize asingle antenna or a set of antennas.

FIG. 13 shows a block diagram 1300 of a base station communicationsmanager 1315 that supports downlink transmission in accordance withaspects of the present disclosure. The base station communicationsmanager 1315 may be an example of aspects of a base stationcommunications manager 1415 described with reference to FIGS. 11, 12,and 14. The base station communications manager 1315 may includeconfiguration controller 1320, downlink transmission manager 1325, andcapability identifier 1330. Each of these modules may communicate,directly or indirectly, with one another (e.g., via one or more buses).

Configuration controller 1320 may transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission. In some cases,the resource configuration is transmitted via RRC signaling, theresource configuration further including a series of RV indices for therepetition window.

Downlink transmission manager 1325 may transmit the downlinktransmission to the UE in accordance with the resource configuration.For example, downlink transmission manager 1325 may transmit one or moreadditional repetitions of the downlink transmission during one or morecorresponding subsequent TTIs of the repetition window, each of the oneor more additional repetitions being associated with a respective RVindex. As another example, downlink transmission manager 1325 maytransmit the first repetition of the downlink transmission, which may bea grant-free downlink transmission, during a TTI of the subset of TTIs,the first repetition being associated with a first RV index. Downlinktransmission manager 1325 may transmit one or more additionalrepetitions of the grant-free downlink transmission during one or morecorresponding subsequent TTIs of the at least one other TTI, each of theone or more additional repetitions being associated with a respective RVindex. Downlink transmission manager 1325 may receive, from the UE, anindication of a successful decoding of the downlink transmission.

In some cases, transmitting the downlink transmission to the UE includestransmitting a first repetition of the downlink transmission during aninitial TTI of the repetition window, the first repetition beingassociated with a first RV index. In some cases, transmitting thedownlink transmission, which may be a grant-free downlink transmission,to the UE includes identifying a subset of TTIs within the repetitionwindow during which a first repetition of the grant-free downlinktransmission is allowed to be transmitted, where the repetition windowincludes the subset of TTIs and at least one other TTI. In some cases,transmitting the downlink transmission to the UE includes transmitting afirst repetition of the downlink transmission during any TTI of therepetition window, the first repetition being associated with a first RVindex.

Capability identifier 1330 may receive, from the UE, an indication of acapability of the UE, where the capability indicates a maximumrepetition window size supported by the UE, a timing within therepetition window for which the UE supports transmission of a firstrepetition of the grant-free downlink transmission, or combinations ofthe same.

FIG. 14 shows a diagram of a system 1400 including a device 1405 thatsupports downlink transmission in accordance with aspects of the presentdisclosure. Device 1405 may be an example of or include the componentsof base station 105 as described herein, e.g., with reference to FIG. 1.Device 1405 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including base station communications manager 1415,processor 1420, memory 1425, software 1430, transceiver 1435, antenna1440, network communications manager 1445, and inter-stationcommunications manager 1450. These components may be in electroniccommunication via one or more buses (e.g., bus 1410). Device 1405 maycommunicate wirelessly with one or more UEs 115.

Processor 1420 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1420 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1420. Processor 1420 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting grant-freedownlink transmission).

Memory 1425 may include RAM and ROM. The memory 1425 may storecomputer-readable, computer-executable software 1430 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1425 may contain,among other things, a BIOS which may control basic hardware or softwareoperation such as the interaction with peripheral components or devices.

Software 1430 may include code to implement aspects of the presentdisclosure, including code to support grant-free downlink transmission.Software 1430 may be stored in a non-transitory computer-readable mediumsuch as system memory or other memory. In some cases, the software 1430may not be directly executable by the processor but may cause a computer(e.g., when compiled and executed) to perform functions describedherein.

Transceiver 1435 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described herein. For example, thetransceiver 1435 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1435 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas. In some cases, thewireless device may include a single antenna 1440. However, in somecases the device may have more than one antenna 1440, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

Network communications manager 1445 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,the network communications manager 1445 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Inter-station communications manager 1450 may manage communications withother base station 105, and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, the inter-station communications manager 1450may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, inter-station communications manager1450 may provide an X2 interface within an Long Term Evolution(LTE)/LTE-A wireless communication network technology to providecommunication between base stations 105.

FIG. 15 shows a flowchart illustrating a method 1500 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 1500 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method1500 may be performed by a UE communications manager as described withreference to FIGS. 7 through 10. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described herein. Additionally or alternatively,the UE 115 may perform aspects of the functions described herein usingspecial-purpose hardware.

At 1505 the UE 115 may receive a resource configuration for reception ofa downlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission. The operations of 1505 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1505 may be performed by a configuration manager asdescribed with reference to FIGS. 7 through 10.

At 1510 the UE 115 may monitor, in accordance with the resourceconfiguration, one or more TTIs of the repetition window for receptionof the downlink transmission. The operations of 1510 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1510 may be performed by a resource monitoringcontroller as described with reference to FIGS. 7 through 10.

At 1515 the UE 115 may attempt to decode the downlink transmissionduring the one or more TTIs of the repetition window based at least inpart on the repetition window size. The operations of 1515 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1515 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

FIG. 16 shows a flowchart illustrating a method 1600 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 1600 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method1600 may be performed by a UE communications manager as described withreference to FIGS. 7 through 10. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described herein. Additionally or alternatively,the UE 115 may perform aspects of the functions described herein usingspecial-purpose hardware.

At 1605 the UE 115 may receive a resource configuration for reception ofa downlink transmission within a repetition window, the resourceconfiguration including an indicator of a repetition window size for thedownlink transmission. The operations of 1605 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1605 may be performed by a configuration manager asdescribed with reference to FIGS. 7 through 10.

At 1610 the UE 115 may monitor for a first repetition of the downlinktransmission in an initial TTI of the repetition window, where therepetition window size is greater than one TTI. The operations of 1610may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1610 may be performed by aresource monitoring controller as described with reference to FIGS. 7through 10.

At 1615 the UE 115 may identify a series of RV indices for therepetition window based at least in part on the resource configuration,each RV index of the series of RV indices associated with a respectiveTTI of the repetition window. The operations of 1615 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1615 may be performed by a decoding manager asdescribed with reference to FIGS. 7 through 10.

At 1620 the UE 115 may attempt to decode the downlink transmissionduring a given TTI of the repetition window based at least in part onthe RV index associated with the given TTI. The operations of 1620 maybe performed according to the methods described herein. In certainexamples, aspects of the operations of 1620 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

FIG. 17 shows a flowchart illustrating a method 1700 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 1700 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method1700 may be performed by a UE communications manager as described withreference to FIGS. 7 through 10. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described herein. Additionally or alternatively,the UE 115 may perform aspects of the functions described herein usingspecial-purpose hardware.

At 1705 the UE 115 may receive a resource configuration for reception ofa grant-free downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the grant-free downlink transmission. The operations of 1705may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1705 may be performed by aconfiguration manager as described with reference to FIGS. 7 through 10.

At 1710 the UE 115 may identify, based at least in part on the resourceconfiguration, a subset of TTIs within the repetition window duringwhich a first repetition of the grant-free downlink transmission isallowed to be transmitted, where the repetition window includes thesubset of TTIs and at least one other TTI. The operations of 1710 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1710 may be performed by aresource monitoring controller as described with reference to FIGS. 7through 10.

At 1715 the UE 115 may monitor for the first repetition of thegrant-free downlink transmission during at least one TTI of the subsetof TTIs. The operations of 1715 may be performed according to themethods described herein. In certain examples, aspects of the operationsof 1715 may be performed by a resource monitoring controller asdescribed with reference to FIGS. 7 through 10.

At 1720 the UE 115 may identify a series of RV indices for therepetition window based at least in part on the resource configuration.The operations of 1720 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1720may be performed by a decoding manager as described with reference toFIGS. 7 through 10.

At 1725 the UE 115 may determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based at least in part on the series of RV indices beginningat a respective TTI of the subset of TTIs. The operations of 1725 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1725 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

At 1730 the UE 115 may attempt to decode the grant-free downlinktransmission during a given TTI of the repetition window based at leastin part on the one or more potential RV indices for the given TTI. Theoperations of 1730 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1730 may beperformed by a decoding manager as described with reference to FIGS. 7through 10.

FIG. 18 shows a flowchart illustrating a method 1800 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 1800 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method1800 may be performed by a UE communications manager as described withreference to FIGS. 7 through 10. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described herein. Additionally or alternatively,the UE 115 may perform aspects of the functions described herein usingspecial-purpose hardware.

At 1805 the UE 115 may receive a resource configuration for reception ofa grant-free downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the grant-free downlink transmission. The operations of 1805may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1805 may be performed by aconfiguration manager as described with reference to FIGS. 7 through 10.

At 1810 the UE 115 may monitor for a first repetition of the grant-freedownlink transmission during any TTI of the repetition window, where therepetition window includes a plurality of TTIs. The operations of 1810may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1810 may be performed by aresource monitoring controller as described with reference to FIGS. 7through 10.

At 1815 the UE 115 may identify a series of RV indices for therepetition window based at least in part on the resource configuration.The operations of 1815 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1815may be performed by a decoding manager as described with reference toFIGS. 7 through 10.

At 1820 the UE 115 may determine one or more potential RV indices foreach TTI of the repetition window, where each potential RV index foreach TTI is based at least in part on the series of RV indices beginningat any TTI of the repetition window. The operations of 1820 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1820 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

At 1825 the UE 115 may attempt to decode the grant-free downlinktransmission during a given TTI of the repetition window based at leastin part on the one or more potential RV indices for the given TTI. Theoperations of 1825 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1825 may beperformed by a decoding manager as described with reference to FIGS. 7through 10.

FIG. 19 shows a flowchart illustrating a method 1900 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 1900 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method1900 may be performed by a UE communications manager as described withreference to FIGS. 7 through 10. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described herein. Additionally or alternatively,the UE 115 may perform aspects of the functions described herein usingspecial-purpose hardware.

At 1905 the UE 115 may transmit an indication of a capability of the UE,the capability indicating a maximum repetition window size supported bythe UE, a timing within the repetition window for which the UE supportstransmission of a first repetition of the grant-free downlinktransmission, or combinations of the same. The operations of 1905 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1905 may be performed by acapability manager as described with reference to FIGS. 7 through 10.

At 1910 the UE 115 may receive a resource configuration for reception ofa grant-free downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the grant-free downlink transmission. The operations of 1910may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1910 may be performed by aconfiguration manager as described with reference to FIGS. 7 through 10.

At 1915 the UE 115 may monitor, in accordance with the resourceconfiguration, one or more TTIs of the repetition window for receptionof the grant-free downlink transmission. The operations of 1915 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1915 may be performed by aresource monitoring controller as described with reference to FIGS. 7through 10.

At 1920 the UE 115 may attempt to decode the grant-free downlinktransmission during the one or more TTIs of the repetition window basedat least in part on the repetition window size. The operations of 1920may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1920 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

At 1925 the UE 115 may transmit an indication that the grant-freedownlink transmission was successfully decoded. The operations of 1925may be performed according to the methods described herein. In certainexamples, aspects of the operations of 1925 may be performed by adecoding manager as described with reference to FIGS. 7 through 10.

FIG. 20 shows a flowchart illustrating a method 2000 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 2000 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2000 may be performed by a base station communications manager asdescribed with reference to FIGS. 11 through 14. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described herein.Additionally or alternatively, the base station 105 may perform aspectsof the functions described herein using special-purpose hardware.

At 2005 the base station 105 may transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission. The operationsof 2005 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 2005 may be performed bya configuration controller as described with reference to FIGS. 11through 14.

At 2010 the base station 105 may transmit the downlink transmission tothe UE in accordance with the resource configuration. The operations of2010 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 2010 may be performed bya downlink transmission manager as described with reference to FIGS. 11through 14.

FIG. 21 shows a flowchart illustrating a method 2100 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 2100 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2100 may be performed by a base station communications manager asdescribed with reference to FIGS. 11 through 14. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described herein.Additionally or alternatively, the base station 105 may perform aspectsof the functions described herein using special-purpose hardware.

At 2105 the base station 105 may transmit, to a UE, a resourceconfiguration for transmission of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission. The operationsof 2105 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 2105 may be performed bya configuration controller as described with reference to FIGS. 11through 14.

At 2110 the base station 105 may transmit a first repetition of thedownlink transmission during an initial TTI of the repetition window,the first repetition being associated with a first RV index. Theoperations of 2110 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 2110 may beperformed by a downlink transmission manager as described with referenceto FIGS. 11 through 14.

At 2115 the base station 105 may transmit one or more additionalrepetitions of the downlink transmission during one or morecorresponding subsequent TTIs of the repetition window, each of the oneor more additional repetitions being associated with a respective RVindex. The operations of 2115 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 2115may be performed by a downlink transmission manager as described withreference to FIGS. 11 through 14.

FIG. 22 shows a flowchart illustrating a method 2200 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 2200 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2200 may be performed by a base station communications manager asdescribed with reference to FIGS. 11 through 14. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described herein.Additionally or alternatively, the base station 105 may perform aspectsof the functions described herein using special-purpose hardware.

At 2205 the base station 105 may transmit, to a UE, a resourceconfiguration for transmission of a grant-free downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the grant-free downlinktransmission. The operations of 2205 may be performed according to themethods described herein. In certain examples, aspects of the operationsof 2205 may be performed by a configuration controller as described withreference to FIGS. 11 through 14.

At 2210 the base station 105 may identify a subset of TTIs within therepetition window during which a first repetition of the grant-freedownlink transmission is allowed to be transmitted, where the repetitionwindow includes the subset of TTIs and at least one other TTI. Theoperations of 2210 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 2210 may beperformed by a downlink transmission manager as described with referenceto FIGS. 11 through 14.

At 2215 the base station 105 may transmit the first repetition of thegrant-free downlink transmission during a TTI of the subset of TTIs, thefirst repetition being associated with a first RV index. The operationsof 2215 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 2215 may be performed bya downlink transmission manager as described with reference to FIGS. 11through 14.

At 2220 the base station 105 may transmit one or more additionalrepetitions of the grant-free downlink transmission during one or morecorresponding subsequent TTIs of the at least one other TTI, each of theone or more additional repetitions being associated with a respective RVindex. The operations of 2220 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 2220may be performed by a downlink transmission manager as described withreference to FIGS. 11 through 14.

FIG. 23 shows a flowchart illustrating a method 2300 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 2300 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2300 may be performed by a base station communications manager asdescribed with reference to FIGS. 11 through 14. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described herein.Additionally or alternatively, the base station 105 may perform aspectsof the functions described herein using special-purpose hardware.

At 2305 the base station 105 may transmit, to a user equipment (UE), aresource configuration for transmission of a grant-free downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the grant-freedownlink transmission. The operations of 2305 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 2305 may be performed by a configuration controller asdescribed with reference to FIGS. 11 through 14.

At 2310 the base station 105 may transmit a first repetition of thegrant-free downlink transmission during any TTI of the repetitionwindow, the first repetition being associated with a first RV index. Theoperations of 2310 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 2310 may beperformed by a downlink transmission manager as described with referenceto FIGS. 11 through 14.

At 2315 the base station 105 may transmit one or more additionalrepetitions of the grant-free downlink transmission during one or morecorresponding subsequent TTIs of the repetition window, each of the oneor more additional repetitions being associated with a respective RVindex. The operations of 2315 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 2315may be performed by a downlink transmission manager as described withreference to FIGS. 11 through 14.

FIG. 24 shows a flowchart illustrating a method 2400 for downlinktransmission in accordance with aspects of the present disclosure. Theoperations of method 2400 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2400 may be performed by a base station communications manager asdescribed with reference to FIGS. 11 through 14. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described herein.Additionally or alternatively, the base station 105 may perform aspectsof the functions described herein using special-purpose hardware.

At 2405 the base station 105 may receive, from a UE, an indication of acapability of the UE, where the capability indicates a maximumrepetition window size supported by the UE, a timing within therepetition window for which the UE supports transmission of a firstrepetition of the grant-free downlink transmission, or combinations ofthe same. The operations of 2405 may be performed according to themethods described herein. In certain examples, aspects of the operationsof 2405 may be performed by a capability identifier as described withreference to FIGS. 11 through 14.

At 2410 the base station 105 may transmit, to the UE, a resourceconfiguration for transmission of a grant-free downlink transmissionwithin a repetition window, the resource configuration including anindicator of a repetition window size for the grant-free downlinktransmission. The operations of 2410 may be performed according to themethods described herein. In certain examples, aspects of the operationsof 2410 may be performed by a configuration controller as described withreference to FIGS. 11 through 14.

At 2415 the base station 105 may transmit the grant-free downlinktransmission to the UE in accordance with the resource configuration.The operations of 2415 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 2415may be performed by a downlink transmission manager as described withreference to FIGS. 11 through 14.

At 2420 the base station 105 may receive, from the UE, an indication ofa successful decoding of the grant-free downlink transmission. Theoperations of 2420 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 2420 may beperformed by a downlink transmission manager as described with referenceto FIGS. 11 through 14.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.A CDMA system may implement a radio technology such as CDMA2000,Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,IS-95, and IS-856 standards. IS-2000 Releases may be commonly referredto as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical andElectronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are releasesof UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR,and GSM are described in documents from the organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NRsystem may be described for purposes of example, and LTE, LTE-A, LTE-APro, or NR terminology may be used in much of the description, thetechniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro,or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellmay be associated with a lower-powered base station 105, as comparedwith a macro cell, and a small cell may operate in the same or different(e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 115 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessby UEs 115 having an association with the femto cell (e.g., UEs 115 in aclosed subscriber group (CSG), UEs 115 for users in the home, and thelike). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a small cell may be referred to as a small cell eNB, a pico eNB, afemto eNB, or a home eNB. An eNB may support one or multiple (e.g., two,three, four, and the like) cells, and may also support communicationsusing one or multiple component carriers.

The wireless communications system 100 or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations 105 may have similar frame timing, andtransmissions from different base stations 105 may be approximatelyaligned in time. For asynchronous operation, the base stations 105 mayhave different frame timing, and transmissions from different basestations 105 may not be aligned in time. The techniques described hereinmay be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device (PLD), discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media maycomprise RAM, ROM, electrically erasable programmable read only memory(EEPROM), flash memory, compact disk (CD) ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother non-transitory medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: receiving a resource configuration forreception of a downlink transmission within a repetition window, theresource configuration including an indicator of a repetition windowsize for the downlink transmission; monitoring, in accordance with theresource configuration, one or more transmission occasions of therepetition window for reception of the downlink transmission;identifying a series of redundancy version (RV) indices for therepetition window based at least in part on the resource configuration;determining one or more potential RV indices for each transmissionoccasion of the repetition window, wherein each potential RV index foreach transmission occasion is based at least in part on the series of RVindices beginning at any transmission occasion of the repetition window;and decoding the downlink transmission during the one or moretransmission occasions of the repetition window based at least in parton the repetition window size and the one or more potential RV indicesfor each transmission occasion.
 2. The method of claim 1, wherein thedownlink transmission is a grant-free downlink transmission and whereinmonitoring the one or more transmission occasions of the repetitionwindow for reception of the grant-free downlink transmission comprises:monitoring for a first repetition of the grant-free downlinktransmission during any transmission occasion of the repetition window,wherein the repetition window comprises a plurality of transmissionoccasions.
 3. The method of claim 2, further comprising: determiningthat a first decoding hypothesis corresponding to decoding the firstrepetition of the grant-free downlink transmission during a giventransmission occasion of the repetition window has failed; and decodinga second repetition of the grant-free downlink transmission using asecond decoding hypothesis during the given transmission occasion of therepetition window based at least in part on the determination that thefirst decoding hypothesis has failed.
 4. The method of claim 3, furthercomprising: decoding the first repetition of the grant-free downlinktransmission using an additional decoding hypothesis during a subsequenttransmission occasion of the repetition window based at least in part onthe determination that the first decoding hypothesis has failed.
 5. Themethod of claim 2, further comprising: transmitting an indication of acapability of the UE, the capability indicating a maximum repetitionwindow size supported by the UE, a timing within the repetition windowfor which the UE supports transmission of the first repetition of thegrant-free downlink transmission, or combinations of the same.
 6. Themethod of claim 2, wherein decoding the grant-free downlink transmissioncomprises: identifying a hybrid automatic repeat request (HARQ) processidentification (ID) for each transmission occasion of the repetitionwindow, wherein the HARQ process ID for each transmission occasion isbased at least in part on the series of RV indices beginning at anytransmission occasion of the repetition window; and combininglogarithmic likelihood ratios (LLRs) of the grant-free downlinktransmission for a given transmission occasion with a previouslyreceived signal based at least in part on the HARQ process ID.
 7. Themethod of claim 2, wherein decoding the grant-free downlink transmissioncomprises: identifying a potential RV index and a corresponding hybridautomatic repeat request (HARQ) process identification (ID) for thegrant-free downlink transmission, wherein each decoding is based on aunique pair of potential RV index and corresponding HARQ process ID. 8.The method of claim 7, wherein identifying the potential RV index andthe corresponding HARQ process ID for the grant-free downlinktransmission comprises: determining a transmission occasion index foreach of the one or more transmission occasions of the repetition window,wherein the corresponding HARQ process ID for a given transmissionoccasion is based at least in part on the transmission occasion indexfor the given transmission occasion.
 9. The method of claim 2, whereinmonitoring the one or more transmission occasions of the repetitionwindow for reception of the grant-free downlink transmission comprises:identifying, based at least in part on the resource configuration, asubset of transmission occasions within the repetition window duringwhich the first repetition of the grant-free downlink transmission isallowed to be transmitted, wherein the repetition window comprises thesubset of transmission occasions and at least one other transmissionoccasion; and monitoring for the first repetition of the grant-freedownlink transmission during at least one transmission occasion of thesubset of transmission occasions.
 10. The method of claim 9, wherein anRV index of the first repetition of the grant-free downlink transmissionis zero (0).
 11. The method of claim 9, wherein each potential RV indexfor each transmission occasion is based at least in part on the seriesof RV indices beginning at a respective transmission occasion of thesubset of transmission occasions.
 12. The method of claim 9, whereindecoding the grant-free downlink transmission comprises: identifying ahybrid automatic repeat request (HARQ) process identification (ID) foreach transmission occasion of the repetition window, wherein the HARQprocess ID for each transmission occasion is based at least in part onthe series of RV indices beginning at a respective transmission occasionof the subset of transmission occasions; and combining logarithmiclikelihood ratios (LLRs) of the grant-free downlink transmission for agiven transmission occasion with a previously received signal based atleast in part on the HARQ process ID.
 13. The method of claim 9, furthercomprising: failing to decode the first repetition of the grant-freedownlink transmission during an initial transmission occasion of thesubset of transmission occasions; and decoding the first repetition ofthe grant-free downlink transmission during an immediately subsequenttransmission occasion of the subset of transmission occasions based atleast in part on failing to decode the first repetition during theinitial transmission occasion of the subset of transmission occasions.14. The method of claim 1, wherein monitoring the one or moretransmission occasions of the repetition window for reception of thedownlink transmission comprises: monitoring for a first repetition ofthe downlink transmission in an initial transmission occasion of therepetition window, wherein the repetition window size is greater thanone transmission occasion.
 15. The method of claim 14, wherein each RVindex of the series of RV indices is associated with a respectivetransmission occasion of the repetition window; and decoding thedownlink transmission comprises decoding the downlink transmissionduring a given transmission occasion of the repetition window based atleast in part on the RV index associated with the given transmissionoccasion.
 16. The method of claim 1, wherein the resource configurationis received via radio resource control (RRC) signaling, the resourceconfiguration further comprising a series of RV indices for repeatedtransmissions of the downlink transmission within the repetition window.17. The method of claim 1, wherein decoding the downlink transmissioncomprises successfully decoding the downlink transmission, the methodfurther comprising: transmitting an indication that the downlinktransmission was successfully decoded.
 18. An apparatus for wirelesscommunication at a user equipment (UE), comprising: a processor, memoryin electronic communication with the processor; and instructions storedin the memory and executable by the processor to cause the apparatus to:receive a resource configuration for reception of a downlinktransmission within a repetition window, the resource configurationincluding an indicator of a repetition window size for the downlinktransmission; monitor, in accordance with the resource configuration,one or more transmission occasions of the repetition window forreception of the downlink transmission; identify a series of redundancyversion (RV) indices for the repetition window based at least in part onthe resource configuration; determine one or more potential RV indicesfor each transmission occasion of the repetition window, wherein eachpotential RV index for each transmission occasion is based at least inpart on the series of RV indices beginning at any transmission occasionof the repetition window; and decode the downlink transmission duringthe one or more transmission occasions of the repetition window based atleast in part on the repetition window size and the one or morepotential RV indices for each transmission occasion.
 19. The apparatusof claim 18, wherein the downlink transmission is a grant-free downlinktransmission and wherein the instructions to monitor the one or moretransmission occasions of the repetition window for reception of thegrant-free downlink transmission are executable by the processor tocause the apparatus to: monitor for a first repetition of the grant-freedownlink transmission during any transmission occasion of the repetitionwindow, wherein the repetition window comprises a plurality oftransmission occasions.
 20. The apparatus of claim 19, wherein theinstructions to decode the grant-free downlink transmission areexecutable by the processor to cause the apparatus to: identify a hybridautomatic repeat request (HARQ) process identification (ID) for eachtransmission occasion of the repetition window, wherein the HARQ processID for each transmission occasion is based at least in part on theseries of RV indices beginning at any transmission occasion of therepetition window; and combine logarithmic likelihood ratios (LLRs) ofthe grant-free downlink transmission for a given transmission occasionwith a previously received signal based at least in part on the HARQprocess ID.
 21. The apparatus of claim 19, wherein the instructions todecode the grant-free downlink transmission are executable by theprocessor to cause the apparatus to: identify a potential RV index and acorresponding hybrid automatic repeat request (HARQ) processidentification (ID) for the grant-free downlink transmission, whereineach decoding is based on a unique pair of potential RV index andcorresponding HARQ process ID.
 22. The apparatus of claim 21, whereinthe instructions to identify the potential RV index and thecorresponding HARQ process ID for the grant-free downlink transmissionare executable by the processor to cause the apparatus to: determine atransmission occasion index for each of the one or more transmissionoccasions of the repetition window, wherein the corresponding HARQprocess ID for a given transmission occasion is based at least in parton the transmission occasion index for the given transmission occasion.23. The apparatus of claim 19, wherein the instructions to monitor theone or more transmission occasions of the repetition window forreception of the grant-free downlink transmission are executable by theprocessor to cause the apparatus to: identify, based at least in part onthe resource configuration, a subset of transmission occasions withinthe repetition window during which the first repetition of thegrant-free downlink transmission is allowed to be transmitted, whereinthe repetition window comprises the subset of transmission occasions andat least one other transmission occasion; and monitor for the firstrepetition of the grant-free downlink transmission during at least onetransmission occasion of the subset of transmission occasions.
 24. Theapparatus of claim 23, wherein a RV index of the first repetition of thegrant-free downlink transmission is zero (0).
 25. The apparatus of claim23, wherein each potential RV index for each transmission occasion isbased at least in part on the series of RV indices beginning at arespective transmission occasion of the subset of transmissionoccasions.
 26. The apparatus of claim 23, wherein the instructions todecode the grant-free downlink transmission are executable by theprocessor to cause the apparatus to: identify a hybrid automatic repeatrequest (HARQ) process identification (ID) for each transmissionoccasion of the repetition window, wherein the HARQ process ID for eachtransmission occasion is based at least in part on the series of RVindices beginning at a respective transmission occasion of the subset oftransmission occasions; and combine logarithmic likelihood ratios (LLRs)of the grant-free downlink transmission for a given transmissionoccasion with a previously received signal based at least in part on theHARQ process ID.
 27. The apparatus of claim 23, wherein the instructionsare further executable by the processor to cause the apparatus to: failto decode the first repetition of the grant-free downlink transmissionduring an initial transmission occasion of the subset of transmissionoccasions; and decode the first repetition of the grant-free downlinktransmission during an immediately subsequent transmission occasion ofthe subset of transmission occasions based at least in part on failingto decode the first repetition during the initial transmission occasionof the subset of transmission occasions.
 28. The apparatus of claim 18,wherein the instructions to monitor the one or more transmissionoccasions of the repetition window for reception of the downlinktransmission are executable by the processor to cause the apparatus to:monitor for a first repetition of the downlink transmission in aninitial transmission occasion of the repetition window, wherein therepetition window size is greater than one transmission occasion. 29.The apparatus of claim 28, wherein each RV index of the series of RVindices associated with a respective transmission occasion of therepetition window; and the instructions to decode the downlinktransmission are executable by the processor to cause the apparatus todecode the downlink transmission during a given transmission occasion ofthe repetition window based at least in part on the RV index associatedwith the given transmission occasion.
 30. An apparatus for wirelesscommunication at a user equipment (UE), comprising: means for receivinga resource configuration for reception of a downlink transmission withina repetition window, the resource configuration including an indicatorof a repetition window size for the downlink transmission; means formonitoring, in accordance with the resource configuration, one or moretransmission occasions of the repetition window for reception of thedownlink transmission; means for identifying a series of redundancyversion (RV) indices for the repetition window based at least in part onthe resource configuration; means for determining one or more potentialRV indices for each transmission occasion of the repetition window,wherein each potential RV index for each transmission occasion is basedat least in part on the series of RV indices beginning at anytransmission occasion of the repetition window; and means for decodingthe downlink transmission during the one or more transmission occasionsof the repetition window based at least in part on the repetition windowsize and the one or more potential RV indices for each transmissionoccasion.
 31. A non-transitory computer-readable medium storing code forwireless communication at a user equipment (UE), the code comprisinginstructions executable by a processor to: receive a resourceconfiguration for reception of a downlink transmission within arepetition window, the resource configuration including an indicator ofa repetition window size for the downlink transmission; monitor, inaccordance with the resource configuration, one or more transmissionoccasions of the repetition window for reception of the downlinktransmission; identify a series of redundancy version (RV) indices forthe repetition window based at least in part on the resourceconfiguration; determine one or more potential RV indices for eachtransmission occasion of the repetition window, wherein each potentialRV index for each transmission occasion is based at least in part on theseries of RV indices beginning at any transmission occasion of therepetition window; and decode the downlink transmission during the oneor more transmission occasions of the repetition window based at leastin part on the repetition window size and the one or more potential RVindices for each transmission occasion.